Implantable medical devices (IMDs), such as implantable cardiac pacemakers, pacemaker-cardioverter-defibrillators, neurostimulators, gastric stimulators, drug pumps, loop recorders, and the like, generally make use of battery power to support the output and functionality of such devices. An IMD is typically designed for use over a period of years, and therefore power efficiency and associated battery consumption is a significant concern.
Some IMDs receive signals from sensors carried by implantable leads. A sensor may be responsive to a sensed condition in the body, such as electrical activity, blood pressure, blood chemistry or a mechanical property. Sensors responsive to sensed conditions may detect or measure a quantity of clinical significance. Some sensors require power to support sensor operation. Examples of powered sensors include ultrasonic sensors, infrared sensors, cameras and the like.
Conventional powered sensors receive power from a battery, which may be positioned with an IMD housing. An IMD delivers power to a sensor by way of a lead that includes a conductor. In general, powered sensors contribute to power consumption and battery drain, and can compromise IMD longevity.